Indicators for biodiversity of tropical forests: problems and solutions.

Climate change has been with us for several decades. Some tropical forest tree species will be unable to disperse and will become extinct. Hence biodiversity loss is inevitable, and strict sustainable forest management (SFM) is not possible in tropical forests. Some of the main international definitions of SFM consider joint optimization of a mix of competing criteria and indicators (C&I), and hence can only lead to compromise solutions in which further loss of biodiversity resources is inevitable. The complexity and diversity of tropical forest tree species means that any assessment of the state of a tropical forest is very uncertain, and almost impossible to achieve through routine cost-limited inventories. The adequacy of some current International C&I monitoring approaches are evaluated specifically in relation to the diversity of tropical forest tree species, and they are found to be inadequate for this purpose. The main weaknesses lie in the partial adoption of an inappropriate indicator methodology, and insufficient consideration of uncertainty issues. It is suggested that the ecosystem approach of the Convention on Biological Diversity enacted within a modern modelling, statistical, and scientific framework would enable understanding of the basic change process, and possibly aid in limiting losses of tropical biodiversity at a global scale.